The present invention pertains to a buckle used in a seat belt device provided for a seat of a vehicle, such as an automobile.
Currently, in various vehicles including automobiles, seat belt devices for protecting occupants in emergency, such as collision, are installed to seats thereof. In order to facilitate the occupant to wear on and off a seat belt, a buckle is normally provided. In general, the buckle comprises a latch member provided with a joggle portion which engages a tongue, wherein the latch member is biased by a spring in such a direction as to engage the tongue.
By the way, the buckle comprises a base made of metal having a U-shaped section composed of side walls and a bottom, wherein the base is attached to a cover made of resin and is accommodated in the cover, and components including the aforementioned latch member are supported by the side walls. When the tongue is inserted into a tongue-insertion opening of the buckle, the end of the tongue is guided by guiding portions formed on the side walls of the metal base having the U-shaped section.
However, in the conventional buckle of this type, when the tongue is inserted into the buckle and is engaged with the buckle, a portion of the tongue to be engaged with a latch member sometimes collides with the aforementioned guide portions and/or the bottom of the base. Since the engaging portion of the tongue is made of metal, the collision between the tongue and the guide portions or the bottom, which are made of metal, makes noise that may jar on an occupant""s nerve who wears the seat belt.
The present invention has been made for solving the above problems, and an object of the present invention is to provide a buckle which can restrain such noise as little as possible that may be made when the tongue is engaged.
To solve the aforementioned problems, the present invention provides a buckle comprising at least: a base made of metal and having a U-shaped section composed of side walls and a bottom; a cover made of resin for housing the base and having a tongue-insertion opening; an operational member made of resin disposed at the tongue-insertion opening for releasing the engagement between a tongue and a latch member; and guide portions formed integrally with the inner surfaces of the side walls for guiding the end of the tongue when the tongue is inserted through the tongue-insertion opening. The tongue is engaged when the tongue is inserted and reaches a predetermined position, and is released from the buckle by release operation of the operational member.
In the invention, the tongue-insertion opening is defined by the cover and the operational member. A portion of the cover for defining the tongue-insertion opening projects for a predetermined distance into the path of movement of the tongue from a surface of the bottom of the base facing the path of the tongue, and a portion of the operational member for defining the tongue-insertion opening projects for a predetermined distance into the path of the tongue from the surfaces of the guide portions facing the path of the tongue. Thus, when the tongue is engaged with the buckle, the tongue touches or collides with at least either the portion of the cover or the portion of the operational member without touching or colliding with the bottom of the base and the guide portions.
In the buckle of the present invention structured as described above, when the tongue is inserted into the buckle through the tongue-insertion opening and is set in the latched state, the tongue touches or collides with the at least one of the portion of the cover made of resin for defining the tongue-insertion opening and the portion of the operational member made of resin for defining the tongue-insertion opening and is prevented from touching or colliding with the guide portions formed on the side walls and the bottom of the base made of metal.
Therefore, noise due to the metal-to-metal contact can be prevented.